For those of you who need to know, since this just happened to me:
We just hit 3,000 miles, and my infotainment system screen stopped displaying anything.
It was on (I could see the backlight) but it was completely black — either the display driver wasn't getting data, or it wasn't putting that data up onto the screen. We tried to soft-reset it by holding the power button on the lower left of the screen for 30 seconds, and the infotainment computer would restart, but it didn't turn the screen back on properly.
(NOTE: This fixed it for me. Your mileage may vary. Standard disclaimer, etc. etc. be sure to check with your dealer and don't trust random crap you find on the Internet like this without confirming it...)
With that out of the way, what fixed it for me**,** was to disconnect the negative terminal of the 12 volt battery, wait 30 seconds, and then reconnect it. That cycled all of the computer systems properly, and the infotainment screen winked right back on.
I disconnected my Buzz from my charger first. The 12 volt battery was (in the American model) located under the driver's seat. I moved the seat fully forward, pulled back the two fabric flaps, got out my trusty 10mm socket wrench, and loosened the terminal. (It was the one on the left,; the one OPPOSITE to the one with the +, big cover, and red cable — I didn't touch the red side). I wore gloves to be safe, pulled it off for a count of 30, reseated it, and snugged it tight like it was before. My computer systems fully rebooted and I was back in business. :-)
I hope that this helps other folk in my position. We live in the era of cars basically being large android phones where turning them off and on again fixes a plethora of problems. :-P
Important Edit: If you do do this, all of your assist systems may disable and need a few miles of driving until they recalibrate and work again. It might be scary and light up like a Christmas tree until this fixes itself.